Electronic device and control means therefor



J. R. DEscH July 9, 1946.

. ELECTRONIC DEVICE AND CONTROL MEANS THEREFOR Filed Nov. '7, 1940 Joscfh R. Dcsch nventor By M His Attorney Patented July 9, 1,946

ELECTRONIC DEVICE AND CONTROL S THEREFOR Joseph R. Desch, Dayton, Ohio, assignor to The National Cash. Register Company, Dayton, Ohio, a corporation of Maryland Application November 7, 1940 Serial No. 364,714

This invention relates to means for producing a selected number of electrical impulses at high speed by the differential operation of a series of electronic devices.

The invention more particularly pertains to the automatic sequential operation of a selected number of a plurality of interconnected cold cathode electron tubes having a common output conductor, which conductor is given an electric potential impulse on the operation of any of the associated electron tubes.

The use of electric impulses to actuate accounting devices and other devices dealing with digital data or other data represented by impulses has created a need for a simple and rapid method of producing such impulses in any desired number; This invention provides an electrical network and circuits interconnecting a plurality of cold cathode diode electron tubes that are rendered conductive one after another at intervals of a few micro-seconds, the state of conductivity of one tube causing conduction to commence in the next tube of the series until the selected 10.C1aims. (Cl.177380) which is hereinafter described with reference to number of electron tubes have been operated.

The change from a state of non-conductivity to a state of conductivity of any of the electron tubes in the series causes an electric potential impulse in a common output conductor. Means is also provided to stop the sequential operation of the plurality of electron tubes at any desired point so that a selected number of electric potential impulses is impressed on the output conductor.

Another feature of the invention is that the circuit permits the automatic sequential operation of the series in either direction, depending at which end of the series the operation is initiated.

Therefore it is the principal object of this invention to provide means to connect a plurality of cold cathode diode electron tubes in a series for automatic successive operation in either direction.

Another object of the invention is to provide means to determine what number of the plurality of electron tubes shall be made to operate in succession.

Another object of the invention is to provide means to cause each electron tube, when operated, to produce an electric potential impulse in a common conductor.

With these and incidental objects in view, the invention includes certain novel features of construction and combinations of parts, the essen tial elements of which are set forth in appended claims and a preferred form or embodiment of.

the drawing which accompanies and forms a part of this specification.

The drawing, the figure shows an electrical network and circuit connecting a plurality of cold cathode and electron tubes for automatic successive operation, an output conductor, and control devices.

General description Referring to the drawing, three cold cathode diode gas discharge electron tubes, designated I, II, and 'III, are shown as the beginning portion of a plurality of electron tubes of any desired number connected together in a group for successive operation. The cold cathode diode electron tube S is provided for starting the automatic successive operation of the tubes of the group in either direction. It will be obvious that hot cathode diodes may be used in place of cold cathode diodes without departing from the principles of the invention. Tubes I, II, and III represent those connected to output conductors 9 and I0 and may represent data, numerical or otherwise. The operation of any one of said electron tubes I, II, III, etc., produces a negative electric potential impulse on output conductor 9 and a positive electricpotential impulse on output conductor I 0. The data-representing tubes I, II, and III are normally connected to operate under control of keys I I and I2 serially from I to III or, if reversing key 8 be used in conjunction with the said keys, from Ill to I. p

The two keys II and I2 represent tubes I and II, respectively. Operation of key I I, followed by operation of starting key I3, will cause the tubes S and I to become conductive successively. 0peration of key l2 in conjunction with the starting key I3 will cause the tubes S and I and II to become conductive successively. Thus, by the use of key I I in conjunction with the starting key I3, a single'electric potential impulse is produced in the output conductors 9 and I0, and,'by the use of key I2 in conjunction with key I3, two electric potential impulses arep-roduced in conductors 9 and I0..

Operation of reversing key 8, key II, and key I3 in conjunction, in the order named, will cause tubes S and III to become conductive. Operation of key 8 in conjunction with key I 3 will cause tubes S, III, II, and I to become conductive in that order. Only two keys, like keys II and I2, are

' shown, but the principle which will'be exemplified in the explanation which follows is applicable to any number of tubes like tubes I, II, and III and associated keys, like keys I I and I2.

The cold cathode gas discharge diode electron tubes S, I, II, and III, which have been selected for a typical embodiment of the invention, have a breakdown requirement of 225 volts for starting a cathode-anode discharge and a potential drop in a discharging tube of approximately 70 volts. Values of operating potentials, resistors, and capacitors are given as an example only as desirable to be used with a tube of the characteristics mentioned and should not be deemed to limit the invention.

Common to tubes S, I, II, and III is a conductor l4 carrying a source of anode potential of 500 volts positive with respect to ground when starting key I3 is closed. A common conductor I5 is provided, to which the anodes I6, I], I8, and I9 are normally connected, each through a linear resistor of 150,000 ohms, respectively numbered 20, H, 22, and 23. Operation of the 1 key II closes contacts 26 connecting the conductor I4 to conductor I5 and opens contacts 28, disconnecting anode I8 of the II tube from conductor I5. Operation of the 2 key I2 closes contacts 2'! connecting the conductor I4 to conductor I5 and opens contacts 29, disconnecting anode I9 of tube III from conductor I5. Thus, operation of the 1 key connects the anodes of all except the II tube to the anode supply conductor I4, and operation of the 2 key connects the anodes of all except the III tube to the anode supply conductor I4.

Each of the cathodes 3|, 32, 33, and 34 is connected to a grounded conductor 30 through 150,000-ohm linear resistors, numbered 25, 36, 31, and 38, respectively.

The anode of each tube is connected to the cathode of the tube following in the series of tubes S, I, II, and III through a linear resistor of 200,000 ohms. Thus, anode I5 of the S tube is normally connected to cathode 32 of the I tube through contacts I2, point 39, conductor 40, resistor M of 200,000 ohms, and conductor 42 to point 55. Anode II of tube I is connected to cathode 33 of the tube II through point 43', through a conductor 44, a resistor 45 of 200,000 ohms, and conductor 45 to point 41. Anode I8 of tube II is connected to cathode 34 of tube III through contacts 28, point 48, conductor 49, resistor 50 of 200,000 ohms, conductor 5|, and point 52. Points 43, 48, and 06 are respectively grounded through condensers 53, 54, and 61, each of .01 microfarad capacity.

The electron tubes are therefore symmetrically connected to a gridlike system of resistances connecting potential supply conductors.

If the 1 key II is depressed, closing contacts 26 and opening contacts 28, and the starting key I3 is thereafter closed, anode voltage is applied to the S, I, and III tubes, and the II tube is disconnected. Capacitors 53, 54, E1, 68, B9, and I charge.

Anode I! of the I tube tends to become 350 volts positive with respect to ground, being connected through resistor 2I of 150,000 ohms to the 500-volt positive conductor I and being connected to ground through resistor 45 of 200,000 ohms and resistor 31 of 150,000 ohms. Anode I8 of the II tube receives no potential. Cathode 32 of the 1 tube tends to become 150 volts positive with respect to ground, being connected at point 55 through resistor 36 of 150,000 ohms to ground and to the 500-volt conductor I5 through resistor II of 200,000 ohms, point 39, and resistor 20 of 150,000 ohms. Anode I5 of the S tube would tend immediately to assume the 350-volt potential of point 39, as determined by resistors 20, 4|, and 35, and cathode 3I would remain at ground potential, being connected through resister 25 of 150,000 ohms to conductor 30, were it not for capacitor 35 of .01 microfarad normally connecting anode I5 through contacts 32 to the 500-volt supply conductor I5 and capacitor 24 of .01 microfarad connecting the cathode 3| to the same 500-volt supply conductor through the same contacts 82.

Due to the charging of capacitors 24 and 35, at the first instant after the closing of switch I3, the cathode 3I and anode it of the S tube rise toward 500 volts and, as the capacitors 24 and 35 charge, the cathode 3I drops back toward ground potential and the anode I5 drops toward the 350-volt potential which point 33 has by that time assumed. At the instant that the potential difference between the anode and the oathode of tube S thus becomes 225 volts or more, conduction occurs in the tube S, and the anode potential drops to about 240 volts positive with respect to ground, due to the combined efiect of resistors 25, 20, M, and 35. Just before tube S became conductive, the potential difference between the anode and the cathode of the 1" tube was 200 volts, as has been explained, and no conduction occurred. As the S tube begins conducting, the potential of point 39, dropping suddenly by approximately volts, causes a potential fall at point 55, bringing the cathode 32 of the I tube to a potential more than 225 volts negative with respect to anode II, which condition initiates conduction in tube I. The potential change at point 55 is determined by the ratio of the resistor 4| to resistor 35, since these resistors are, in effect, a voltage divider. As conduction begins in tube I, point 43 receives a drop in potential from the normal 350 volts to 265 volts, which drop in potential is impressed on point 41 and is sufficient to begin conduction in tube II were the anode I8 of the II tube connected to the supply conductor I5. However, due to the opening of contacts 28, anode I8 receives no operating potential. Thus, only the I tube, of tubes I, II, and III, is rendered conductive, as conduction in tube II is necessary to cause tube III to break down.

If the 2 key I2 were operated in conjunction with key I3 instead of the 1 key I I, as described, the conduction would occur in the S, I, and II tubes successively, as the II tube would then have anode potential, whereas the III tube anode would be disconnected.

Therefore, operating the 1 key II in conjunction with the starting key IEI causes the S and the I tubes to conduct in succession, and the 2 key I2 used in conjunction with the starting key causes the S, I, and II tubes to conduct in succession. Such successive conduction may occur with any number of tubes connected as shown.

Operation of key 8 in conjunction with a key I I or I2 and with the key I3, in that order, causes the data-representing tubes I, II, and III to be operated serially in reverse order. Operation of key 8 opens contacts I2, disconnecting anode I6 from point 39 so-that the conduction in tube S Will not break down tube I, closes contacts I3 to connect anode I6 through resistor 11 of 150,000 ohms to the anode supply conductor I4, closes contacts I5, which connects cathode 3| of the S tube by means of conductor 00, through resistor 16 of 200,000 ohms, to anode II) of the- III tube, opens contacts, 82 disconnecting capacitors 24 and 35 from conductor I5, and closes contacts 8I grounding capacitors '24 and}. 35. This switching :action of key 8 causes the risein potential of cathode 3I of tube 5, on conduction of tube S to be impressed on the anode of the last tube of the series, tube III in this embodivment, which causes the sequential operation of tubes I, II, and III to commence with the III tube and to proceed toward the "I tube until stopped by reason of the operation of a key, like key II, which disconnects the anode of 'the'tube next higher in order from the source of anode potential. Considering the specific example of operating the key II, the key 8, and the key I3, in the order given, the S tube will begin conducting, followed by conduction in the IIIftube. Operation of key 8 connectspoint 18 with point 90 by closing contacts 15,. disconnects the anode I6 from point 39 by the opening of contacts 12,

and connects anode I6 to conductor I4 through resistor 11 of 150,000 ohms by the closing of contacts 13., Under these conditions, when starting key I3 is closed, anode I6, which is connected to the 500-volt conductor I4, and cathode 3| are temporarily grounded by the charging of the now grounded capacitors 24 and 35. The anodes and the cathodes of tubes I, II, and III assume their potentials, as has been explained in the example or normal operation, and capacitors 53, 54, 61, 68, 69, and are charged as capacitors 24 and 35 are being charged. Thereafter, point 18 and cathode 3| rise toward 150 volts positive, and anode I6 rises toward 500 volts positive; Tube S breaks down when anode I6 and cathode 3| reach a potential difference of-225 volts, and conduction begins therein, whereupon the oathode 3| rises still further to about 260 volts due to the combined action of resistors 11, 25, 16, and 23. Under these conditions, Point 90 and anode I9 of tube III, before tube S begins conducting; and

while capacitor 24 is'charging, are about 350 volts positive, being connected to point 18 through resistor 16 of 200,000 ohms, which is grounded through resistor 25 of 150,000 ohms and connected to the 500-volt conductor I5 through re-' sistor 23 of 150,000 ohms. Cathode 34 being at 150 volts positive with respect to ground and anode I9 being at 350 volts positive, tube III will not conduct. As tube S begins conducting, point 18 reaches 260 volts, causing anode I9 to rise toward 400 volts,, which causes tube III to break down. On tube III conducting, point 52 rises in potential from 150 volts positive with respect to ground to 245 volts, which potential rise in part is impressed on point 48 and, if plate I8 of tube II were not disconnected by reason of key II being depressed, would be sufficient to causethe tube II to break down, followed by tube I breaking down, as cathode 33 would rise from 150 volts to abOut 240 volts,

The normal sequential operationof the tubes from I to III is initiated and maintained by the drop'in potential of the anode as a tube begins conducting, breaking down the following tube,

'-whereas in the reverse sequential operation the cathode rise in potential is so utilized.

The operation-initiating impulseis taken from the anode of the starting tube S for normal operation and from the cathode of the starting tube S for reverse operation.

In'considering tubes I, II, and III, extended into a series of ten, each tube representing a digit in a denomination of the decimal system, includ-' ing a zero tube following the tube representing nine, it will be apparent that operation of such a series in reverse will cause a number of tubes to conduct in sequence, which represents the complement, on the base of nine, of the digit represented by the data key depressed. For instance,

Thus,'by. the use of the same data key, represented by the keys II and I2, either data representing a number or its complement may be derived in the form of electric potential impulses I impressed on output conductors 9 and I0 in a manner to be described.

The starting tube S and the three data tubes I, II, and III and their interconnections shown in the drawing are sufficient to illustrate how any number may be so interconnected.

Between point 43 and ground wire 30 is a ca p-ac'itor 53 of .01' microfarad, which acts as an energy reserve by charging before tube I breaks down, causing a strong sharp positive potential impulse at point 55 when the I tube begins to conduct. Anode I1 is kept from dropping to its final potential while capacitor-53 is discharging, thus causing the cathode 32 to rise momentarily to about 300 volts above ground potential, after which it drops back to about 190 volts. Similar capacitors 54 and B1 are shown connected to the anodes of the II and the III tubes, respectively, and are provided for the same purpose in connection with the potential impulse produced at points 41 and 52. It will be apparent that anodes 'II, I8, and I9 will drop in potential after the discharge of capacitors '53, 54, 61, 68, 69, and I0,- due to conduction'in the associated tubes, causing a negative impulse at points 43, 48, and 66,

Output conductor I0, grounded through a 000-ohm resistor 65, is connected to each of the cathodes of the tubes I, II, III, etc., eachthrcugh a capacitor of .002 microfarad, like capacitors 55, 51, and 58, and receives a positive potential impulse of approximately volts each time one of the tubes I, II, III, etc., becomes conductive. Output conductor 9, grounded through a10,000-ohm resistor BI, is connected to each of H the anodes through a capacitor like capacitors 50' 58, 69; and I0, each of .002 microfarad, and condoctor 9 receives a negative potential pulse each time one of said tubes becomes conductive.

Thus, by depressing the I or 2 key in conjunction with starting key I3, one or two positive potential impulses may be sent out on the conductor I0, and one or two negative potential impulses may be sent out on conductor 9. With the values given for the resistors and the capacitore; the total time elapsing for the operation of the several tubes shown is a matter of a few miere-seconds.

In the example of normal operation given with the 1 key II depressed, the anode plate I8 of the II tube wasgiven no positive potential;

used to connect the anode source of potential to conductor l5, and any method other than keys I I and 12 may be used tointerrupt the successive operation of the tubes, without departing from the principle governing the automatic and successive operation of the tubes. It will also be apparent that the negative or positive impulse necessary to initiate a normal or reverse sequential operation of the data tubes may be derived from any desired source other than tube S.

While the form of mechanism herein shown and described is admirably adapted to fulfill the objects primarily stated, it is to be understood that it is not intended to confine the invention to the one form or embodiment herein disclosed, for it is susceptible of embodiment in various forms all coming within the scope of the claims which follow.

What is claimed is:

1. In combination, a plurality of cold cathode gas discharge tubes; means including a resistance connecting the anode of one tube with the cathode of another tube; common means for supplying anode-cathode potential to the tubes slightly under that necessary to cause conduction therein, said means including a resistance between each anode and the common supply means; and means to cause the cathode potential of one tube to become more negative to the point of causing conduction in said tube, said ensuing conduction causing a drop in anode potential, due to the re-.

sistance between the anode and the supply means, which drop in potential is impressed on the oathode of the tube to which the anode is connected, such cathode drop in potential in the secondmentioned tube causing conduction to commence therein, and by the same method to cause conduction in all the tubes in sequence.

2. In combination, a plurality of cold cathode gas discharge tubes each having an anode and a cathode; a positive electric supply conductor; a negative electric supply conductor, the potential difference between said positive and negative conductors being greater than the breakdown potential of a tube; a plurality of similar parallel circuits joining said conductors, each circuit including resistances greater than the internal resistance of a conductive tube, and the anode of one tube and the cathode of another tube being connected to each one of said circuits with a portion of the resistance between the connecting points so as to give any one tube an anode-cathode potential slightly less than the breakdown requirements; and means to cause a discharge in the first one of the tubes, whereby the resulting potential drop of the anode causes a potential drop in the connected cathode of the next tube, causing it to discharge and in turn to cause a discharge throughout the remainder of the plurality of tubes in sequence.

3. A plurality of diode gas discharge tubes arranged in a sequential operative series; means including a resistance between each two tubes to connect the tubes in the series, the anode of a tube being connected to the cathode of an adjacent tube; common means to supply anode-cathode potential to all tubes, said means including a resistance between each anode and the common supply means and a resistance between each cathode and the common supply means, the supplied anode-cathode potential in a given tube normally being less than that necessary to cause conduction therein; and means to change the potential of one of the electrodes of the first tube in the series to a point where conduction takes place in said tube, the ensuing change in the potential of the other electrode due to the mentioned resistance between it and its supply means being impressed on the connected electrode of the next tube of the series, causing it to change potential to a point where conduction begins in said next tube, which in turn causes the firing of the next tube in the series.

4. In combination, a plurality of electron tubes; means connecting the tubes in a series so that the operation of the tube at either end of the series will cause the remainder of the tubes to be operated in sequence automatically to the other end of the series; a first conductor common to all the tubes; means to produce a positive electric potential impulse on said conductor each time a tube is operated; a second conductor common to all the tubes; and means to produce a negative impulse on said conductor each time a tube is operated.

5. A plurality of cold cathode gas discharge tubes arranged in'a sequential operative series; means to connect the tubes in the series, the anode of the preceding tube being connected through a resistance to the cathode of the succeeding tube; means to supply anode-cathode potential to all tubes, said means including a resistance in the anode supply conductor of one tube arranged in series through said connecting means with a resistance in the cathode supply in the following tube, the anode-cathode potential in any tube being less than that necessary to cause conduction; means to lower the cathode potential of the first tube in the series to a point where conduction takes place in said tube, the ensuing drop in anode potential due to the mentioned resistance in its supply conductor being impressed on the cathode of the following tube, which lowers said cathode in potential to a point where conduction begins in said following tube, causing its anode to drop in potential, thus firing the next tube in sequence; and a common output conductor connected to all the cathodes each by means of an electric field whereby the potential rise in any of the cathodes as said tube begins to conduct is impressed upon said output conductor.

6. A plurality of cold cathode discharge tubes arranged in a sequential operative series; means to connect the tubes in the series, the anode of the preceding tube being connected through a resistance to the cathode of the succeeding tube;

means to supply anode-cathode potential to all tubes, said means including a resistance in the anode supply conductor of one tube arranged in series through said connecting means with a resistance in the cathode supply in the following tube, the anode-cathode potential in any tube being less than that necessary to cause conduction; means to lower the cathode potential of the first tube in the series to a point where conduction takes place in said tube, the ensuing drop in anode potential due to the mentioned resist- 1 ance in its supply conductor being impressed on the cathode of the following tube, which lowers said cathode in potential to a point where cond-uction begins in said following tube, causing its anode to drop in potential, thus firing the next tube in sequence; a common output conductor connected to all the cathodes by means of an electric field whereby the potential rise in any of the cathodes as said tube begins to conduct is impressed upon said output conductor; and means to disconnect the operating potential from the tube following the one it is desired to operate last in the series.

7.In combination, a series of electron tubes each having an anode and a cathode; a common conductor; means connecting each anode to the common conductor; and means associated with each tube which when operated connects the common conductor to a second conductor and disconnects the anode of the tube next in the series from said first-mentioned conductor.

8. In combination, a plurality of electron tubes arranged in a series; means connecting thetubes so that they are automatically operable in sequence from one end of the series to the other end of the series in either direction; means to control the direction of operation; and a plurality of means each when operated acting to interrupt the operation at a certain tube in the series, each of said means determining how many tubes shall operate in sequence in one direction and how many tubes shall operate in sequence in the other direction, said determined numbers of tubes being complementary to the total number of tubes in the series less one.

9. In combination, a series of electron tubes each having an anode and a cathode; means connecting the tube for automatic sequential operation beginning at either end of the series, said operation being commenced at one end of the series by applying a positive potential impulse to the anode of the beginning tube at that end, and

10 said operation being commenced at the other end of the series by applying a negative potential impulse to the cathode of the beginning tube at I said other end; an operation-initiating electron tube; and means for connecting the initiating tube to one end or the other of said series, said means being arranged so that the operation of the initiating electron tube when connected to one end of the series will supply a positive electric initiating impulse to the anode of the beginning tube and when connected to the other end of the series will supply a negative electric initiating impulse to the cathode of the beginning tube at said other end.

10. In combination, an electrical network comprising two electric potential supply conductors connected by a plurality of resistance paths arranged in parallel; a plurality of electron gas discharge tubes having a breakdown requirement less than the potential difference between the supply conductors; and means connecting one of the electron tubes between each pair of adjacent resistance paths at points so that the potential difference between the anode and the cathode is slightly less than the breakdown requirement and so that the potential difference between each of the electrodes and its supply conductor is the same, a breakdown caused in one of the tubes causing a breakdown in the next adjacent tube on either side. I

JOSEPH R. DESCH. 

